Iris Fixation via External Pentagram Suturing
May 5th, 2022
The present protocol describes how a 10-0 polypropylene suture crosses the anterior surface of the iris, forming a pentagram to prevent both iris and pupil from moving toward the cornea. This can be combined with subsequent keratoplasty to cure bullous keratopathy with extensive anterior synechia of the iris.
The pentagram suturing anterior chamber plasty, or PSACP, provides an adequate space basis for DSAEK to help cure the bullous keratopathy caused by a vanished anterior chamber or extensive anterior synechia. Begin by displaying the range of anterior synechia by ASOCT and UBM to design the position of incisions. Mark the five scleral puncture points 1.5 millimeters posterior to the limbus with 1%crystal violet solution.
After ensuring that the circular distance between the adjacent puncture points is 72 degrees, remove the edematous epithelium of the cornea with a sclera tunnel knife. Make a one millimeter limbus incision and inject cohesive viscoelastic to separate the anterior synechia of the iris. Perform blunt separation for PAS.
Insert the 16 millimeter STC-6 needle one millimeter beside one of the puncture points into the anterior chamber and retrieve it across the surface of the iris within the bore of a 29 gauge syringe from another puncture point with a circular distance of 144 degrees. When the STC-6 needle comes out of the anterior chamber, select the next insertion point. Repeat this process until the retention sutures in the anterior chamber form a pentagram-like barrier on the surface of the iris and pupil.
Tie a surgical knot from the initial insertion point and embed it into the superficial sclera under the bulbar conjunctiva. In the first case study without PSACP one day post-anterior chamber plasty with synechia separation and PKP, the 68-year-old female showed no PAS with the ASOCT and BCVA improved to 20/1000 with elevated IOP. 12 weeks after surgery, the patient showed 360 degrees PAS with the UBM and BCVA decreased to 20/1600.
The IOP was uncontrolled over 25 millimeters of mercury and the bullous keratopathy reoccurred. In the second case study, a 75-year-old female received PSACP where pentagram sutures were placed as a barrier in front of the anterior surface of the iris. No PAS was seen with ASOCT or UBM until 12 weeks post-surgery.
In 24 weeks post DSAEK and PSACP, no corneal edema was observed and one clock hour PAS was demonstrated with UBM, with BCVA 20/66. IOP remained normal without any medication post-surgery. In the third case study, a 69-year-old female received PSACP and showed two clock hours PAS with ASOCT on day one post-surgery.
The patient showed six clock hours PAS with UBM in 24 weeks post-surgery and received PKP. On one week post PKP, mild edema was seen in the cornea graft and six clock hours PAS with the ASOCT with improved BCVA 20/400. IOP remained normal without any medication post-surgery.
Ensure that the adjacent puncture points are at a circular distance of 72 degrees and that puncture points are 1.5 millimeters posterior to the limbus without touching the anti-glaucoma filtration bleb. Iris fixation via PSACP utilizes only one 10-0 proline suture to form a stable anterior chamber with adequate spaces for over a month. This can be followed up with DSAEK or PKP for treating bullous keratopathy with extensive anterior synechia of the iris.
Overview
This protocol outlines the pentagram suturing anterior chamber plasty (PSACP) technique using a 10-0 polypropylene suture to stabilize the iris and pupil. This method is aimed at treating bullous keratopathy associated with extensive anterior synechia.
Key Study Components
Area of Science
- Ophthalmology
- Corneal surgery
- Anterior chamber management
Background
- Bullous keratopathy can result from extensive anterior synechia.
- PSACP creates a stable anterior chamber environment.
- Previous methods may not adequately prevent postoperative complications.
- Understanding the anatomy and surgical techniques is crucial for success.
Purpose of Study
- To describe the PSACP technique for iris stabilization.
- To evaluate the effectiveness of PSACP in preventing postoperative complications.
- To provide a detailed surgical protocol for researchers and clinicians.
Methods Used
- Utilization of ASOCT and UBM for preoperative assessment.
- Marking scleral puncture points for suture placement.
- Performing blunt separation of anterior synechia.
- Creating a pentagram-like suture pattern to stabilize the iris.
Main Results
- PSACP showed no postoperative anterior synechia in case studies.
- Improvement in best-corrected visual acuity (BCVA) was noted.
- Intraocular pressure remained stable without medication.
- Corneal edema was effectively managed post-surgery.
Conclusions
- PSACP is an effective technique for managing bullous keratopathy.
- It provides a stable anterior chamber and prevents complications.
- Further studies may enhance understanding and application of this method.
Frequently Asked Questions
Executive Industry Relevance
Stabilizing the anterior chamber in eyes with extensive anterior synechia is critical for enabling downstream corneal interventions and reducing the risk of recurrent bullous keratopathy. The pentagram suturing anterior chamber plasty (PSACP) technique provides a reproducible method to maintain anterior chamber architecture, supporting surgical planning and translational continuity in complex ophthalmic cases. This approach addresses a key inflection point in the surgical management pipeline for patients requiring DSAEK or PKP.
Strategic Applications in Biopharma R&D
Early Discovery & Target Validation
- Enables mechanistic interrogation of anterior chamber stability in disease-relevant ocular models.
- Supports functional validation of iris fixation strategies for translational research.
- Facilitates predictive confidence in surgical outcomes for complex anterior segment pathology.
Screening & Assay Development
- Provides a standardized surgical model for evaluating anterior chamber interventions.
- Enables reproducible assessment of iris fixation efficacy using imaging endpoints.
- Supports quantitative measurement of anterior synechia recurrence and chamber stability.
Translational & Preclinical Research
- Aligns with disease-relevant endpoints such as corneal edema resolution and intraocular pressure normalization.
- Enables continuity from surgical intervention to preclinical validation of corneal graft outcomes.
- Supports risk-adjusted advancement of new fixation techniques in translational ophthalmology.
Pipeline & Workflow Integration
PSACP is positioned at the interface of surgical discovery and preclinical validation, enabling robust hypothesis testing and workflow standardization for anterior chamber reconstruction.
- Discovery Biology: Facilitates hypothesis-driven evaluation of iris stabilization in the context of anterior synechia.
- Screening: Provides reproducible imaging and clinical endpoints for comparing fixation strategies.
- Analytics: Enables quantitative tracking of PAS recurrence, corneal edema, and intraocular pressure.
- Translational Research: Bridges surgical technique optimization with preclinical graft survival and function studies.
- Enterprise Reuse: Establishes a reusable surgical model for iterative testing of anterior chamber interventions.
Operational & Enterprise Impact
- Scientific Value: Increases predictive confidence in anterior chamber stability and reduces mechanistic ambiguity in surgical outcomes.
- Operational Value: Standardizes fixation procedures and imaging assessments for reproducibility across studies.
- Strategic Value: Improves go/no-go decision-making for advancing new surgical techniques and adjunct therapies.
- Portfolio Impact: Supports risk-adjusted prioritization of anterior segment interventions in translational pipelines.
Implementation Considerations
- Requires expertise in anterior segment surgery and ocular imaging modalities (ASOCT, UBM).
- Demands access to specialized microsurgical instruments and suture materials.
- Necessitates cross-team standardization of imaging and clinical outcome measures.
- Adaptation may be needed for different ocular models or patient populations.
- Limitations include the need for precise suture placement and monitoring for PAS recurrence.
